Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 15238f55fde952dd…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: ab5d6ae534785e3210c2a0282361c99a SHA-1: 60ad80e0427433782560a9408a56c1808c7b5244 SHA-256: 15238f55fde952dda643b55f6ae7f26ff0aee4c4cb3f7f1a7c8d3f29ecc156af
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a critical finding. The macros utilize the RUN function and a CALL function to execute code, and reference a URL that is likely used to download a second-stage payload. The presence of ShellExecute API calls further supports the execution of external code. The ClamAV detection ID 'Doc.Downloader.Docusign0521-9864805-0' also indicates a downloader functionality.

Heuristics 6

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • ClamAV: Doc.Downloader.Docusign0521-9864805-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Docusign0521-9864805-0
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://avra.dtmh.gr/ds/231120.gif
    • https://avra.dtmh.gr/ds/231120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
8b13557c7c753c9d978b32b1134fab6c924344fc591b06bd0cf8f75d5ca380b6
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6060 bytes